SENSORS AND ACTUATORS B-CHEMICAL, vol.320, 2020 (SCI-Expanded)
In the presented study, gold nanoparticle assembled peptide nanotube (AuNP-PNT) modified graphite sensor system was offered for the first time for the impedimetric analysis of a potential prostate cancer biomarker, circulating miRNA 410, which is secreted by prostate cancer cells and is released into peripheral blood system. The proposed disposable sensor platform was easily constructed through one-pot synthesized nanocomposite modification with physical adsorption. AuNP-PNT nanocomposite and sensor surface features were identified with physicochemical, microscopic and electrochemical methods. The parameters which affect the sensor performance such as nanocomposite adsorption, probe DNA immobilization and hybridization process time-temperature were investigated and optimized. High sensitivity and low detection limit were established as 3.90 fM with a wide linear range from 10 fM to 300 pM for the impedimetric recognition of miRNA 410 based on the hybridization process. Selectivity experiment results proved that the developed surface captured the target miRNA with good base discrimination ability. Furthermore, the fabricated disposable sensor system was successfully applied in peripheral serum with good recovery. The proposed sensor system with its outstanding features such as cheapness, easiness, time effectiveness and sensitivity can be applied as a new sensor surface for the electrochemical detection of important analytes.